1. Field of the Invention
This invention relates to a punch for a punch press and more particularly to a punch which is mounted on a punch installing portion of a punch press and is useful, for example, in case of shearing and separating rectangular small products from a rectangular large sheet material.
2. Description of the Prior Art
In a punch press such as a turret punch press or the like, there is provided a positioning device which will move in X-axis and Y-axis directions to position a large rectangular sheet material against punching tools mounted on the punch press. That is to say, in a punch press, moving and positioning the sheet material against the punching tools by using positioning device, punching is performed on a desired location of a sheet material.
Meanwhile, in recent years, in order to produce a wide variety of products by small number for each variety, a manufacturing method is adopted in which various punchings are performed on a large sheet material in advance, and then thereafter the respective various products each having various punched holes, are sheared and separated from said sheet material.
The above-described manufacturing method is conventionally performed, for instance, in an arrangement in which a shearing machine having an L-shaped shearing blade is disposed adjacent to a punch press. And, in the arrangement, after the punching is performed on the sheet material at the turret punch press, the sheet material will be moved to a side of the shearing machine and holded by a positioning device of the shearing machine. Thereafter, process of positioning of the sheet material and those of shearing and separation of small products from the sheet material are automatically performed by the shearing machine.
In the prior art as described above, however, a transport device to transport the sheet material from the punch press to the shearing machine is required. Therefore the arrangement becomes complicated, and moreover, time is consumed to transport the sheet material, resulting in that work efficiency becomes low. Further, since the sheet material is holded by the positioning devices of shearing machine as well as that of the punch press, positioning error of the sheet material on the punch press and that of on the shearing machine is added up, resulting in that there occured a problem that processing accuracy will be lowered.